1. Field of the Invention
This invention is a plastic vacuum canister (referred to as a PLANISTER from this point onward) which relates to the technology of vacuum packaging in rigid, cylindrical containers of plastic or metal. The vast majority of vacuum packages in use today, especially for consumer goods, are that of "disposable" or "throw-away type". The PLANISTER provides an economical method of applying recyclable vacuum containers to a wide variety of uses. Also, the PLANISTER provides a secondary vacuum seal using readily-available materials. Further, the PLANISTER is intended to provide a moisture-proof container for both shipping and/or storage of various materials.
2. Description of the Prior Art
______________________________________ R. B. Waite Patent 1,509,916 (Sep. 1924) Thomas J. Rossi Patent 3,943,987 (Mar. 1976) Anthony & Richard Iavarone Patent 4,093,009 (Jun. 1978) Ronald J. Corn Patent 4,591,055 (May 1986) Gordon Geasland Patent 4,779,736 (Oct. 1988) ______________________________________
It is known in the prior art that numerous patents have been issued for vacuum-sealing cylindrical devices of various materials. In the case of GEASLAND, U.S. Pat. No. 4,779,736 is demonstrated a means of sealing thermoplastic pipe at both ends and providing an aperture at one end for inserting and removing material. The GEASLAND device is very effective in providing a seal that is both liquid-tight and applicable to a wide-variety of uses. However, in each claim of the GEASLAND Patent, the aperture so provided is smaller than the cross-sectional area of the cylinder being used. This is to say that, for example, three-inch PVC pipe using the GEASLAND method will have a usable opening of less that three inches for inserting and removing material. Also, the necessity of heat-sealing thermoplastic pipe is not a readily available means for the typical consumer. Such heat-sealing is better suited to commercial and/or industrial users. The GEASLAND Patent does not provide the equivalent of a secondary O-ring vacuum seal as is provided with the PLANISTER. The GEASLAND Patent, by description, suggests cylinder lengths measured in feet (to make the process practical) whereas PLANISTERS are suitable in lengths of from just a few inches to ten feet in length.
In the Case of CORN, U.S. Pat. No. 4,591,055 there is the use of a thermoplastic overwrap that is not necessary with the PLANISTER. The PLANISTER does not provide the semaphore "loss of vacuum" signal as is provided with the CORN Patent, however, the PLANISTER provides a secondary vacuum seal via O-ring that is not present in the CORN device.
The vacuum devices for IAVARONE (et al), U.S. Pat. No. 4,093,009 refer to flexible containers, whereas the PLANISTER is specifically intended for resilient materials.
In the case of ROSSI, U.S. Pat. No. 3,943,987 there is the use of an evacuation valve on the vacuum-sealed device proper, which is not necessary with the PLANISTER. Such device is located at the vacuum pumping source instead. Also, the ROSSI device has no secondary O-ring vacuum seal as is found on the PLANISTER.
The secondary O-ring seal is also not present with U.S. Pat. No. 1,509,916 granted to R. B. WAITE (September 1924).